1. Field of the Invention
The present invention relates to a device to drain a fibrous pulp suspension.
2. Background of the Invention
A device for draining a fibrous pulp suspension is know which includes an arched surface as, for example, a roll. Moreover, it is known to have a portion of the circumference of the arched surface encircled by a screen belt. The screen belt and sleeve surface of the roll create an inlet slit for draining the fibrous pulp suspension.
Such a device is described in WO 96/08600. In this reference, the arched surface is a roll with openings that open into the roll interior. The roll is, moreover, placed under suction. A portion of the circumference of the roll surface is surrounded by a substantially impermeable belt.
This device is disadvantageous because the fibers adhere to the impermeable belt during operation. The fibers very quickly create fiber clumps and seriously interfere with the operation of the device. Further, to clean the device, it is necessary to stop the machine and disassemble the belt.